You can change/add/hide fields via Forms builder in Studio. Here - https://una.io/page/view-article?id=12 - is a tutorial on how to do it with Categories, but it gives an idea on the method and approach for other fields as well. No need for custom development. Also more info here - https://github.com/unaio/una/wiki/Forms-Builder
Cool, thank you Andrew. Now I understand the logic!
The last link is where i discovered a forms builder version that would be perfect for UNA